Clutch mechanism for transmissions



p 9 1932- E. A. THOMPSON Q 1,354,281

CLUTCH MECHANISM FOR TRANSMISSIONS Filed Aug.. 2, 1926 2 Sheets-Sheet 1 Aprifi R, 1%2. E. A THOMPSON CLUTCH MECHANISM FOR TRANSMISSIONS 2 Sh'eets-Sheet 2 Filed Aug. 2 1926 Patented Apr. 19, 1932 UNITED STATES PATENT OFFICE EARL A. THOMPSON, OF PORTLAND, OREGON, ASSIGNOR- '10 GENERAL MOTORS IPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE CLUTCH MECHANISM FOR TRANSMISSIONS Application filed August 2, 1926. Serial No. 126,639.

My invention relates to new and useful improvements in clutch mechanism for transmissions and has for its principal object the provision of such a mechanism which is relatively simple and inexpensive in construction, which may be constructed with the addition of only a very few parts to the transmission now commonly in use and in which speed changes may be effected without clash.

A further object of the invention resides allowed for synchronization, during the shifting of the elements, so that the members may be intermeshed without clash.

A still further object of the invention resides in the provision of shift rods adapted to be operated through the usual form of shift lever and means whereby the movement of the shift rods may initially set into operation the synchronizing mechanism and then operate the shiftable element to be meshed with the desired speed gear.

As another object of the invention I provide novel means for lubricating the bearings of certain of the gears, said lubrication being 4 the clutch shaft 2, as shown more particularly in Fig. 1 of the drawin s, and this re- 80 forced to the bearings under pressure.

VVith the above and other objects in view, which will appear as the description proceeds, my invention consists in the novel details of construction, and arrangements of parts, described in the following specification and illustrated in the accompanying drawings, and -while I have illustrated and described the preferred embodiments of the invention, as

they now appear to me, it will be understood that suchchanges may-be made as will fall Wltllllltllfl scope of the appended claims.

In the drawings: Fig. 1 is a longitudinal .vertical section through the transmission with parts shown in elevation.

section on the plane'indi'cated by line 22 of Fig. 1 with parts shown in elevation.

gaging. member therefor, this view being Fig. 2 is-a fragmental transverse vertical taken from that side of the transmission opposite to that shown in Fig. 1.

Fig. 4 is a detail of the gear bearing. Fig. 5 is a fragmental detail, partly in section and partly in elevation, showing a slight- 1y modified form of shifter rod and mechanism therefor,

Fig. 6 is a fragmental detail showing a. modified form of coupling, i

Fig. 7 is a fragmentaldetail, partly in section and partly in elevation, showing a modi fication of shifter rod construction and positioning, and

Fig. 8 showsa modifiedform of stop for 65 the yokes.

The invention is illustrated and described as embodied in a motor vehicle change-speed gear assembly wherein it :is of exceptional utility. v l a In the drawin sion casing or ho lsing of usual construction,

2 the engine clutch shaft, 3 the driven shaft, and lathe counter shaft. The clutch shaft 2 is supported by the roller'bearing 5 and the driven shaft 3 by the ball bearing 6. The forward end of the driven shaft 3 is reduced as shown at 7 to telescope within the end of duced end of the driven sha is supported by the roller bearing 8. The inner end of the clutch shaft 2 is enlarged as shown at 9 and provided with the conical recess 10, teeth 11 being formed interiorly of the recess adjacent the outer end thereof, thus constituting one element of a jaw clutch. The enlarged end 9 is provided with the circumferentially extending groove 12 for a purpose to be later described.

. a i no The driven shaft 3 is splined and has secured thereto the conical member-1 3 which is received within the recess 10 and normal-f ly out of engagement therewith so that the enlarged recessed end of the shaft 2 is n r- 06 mally freely rotatable relative to the member, the shaft 2 being longitudinally slida'ble,

in a manner to be later described, so as to form engagement between, the conical member'13 and the wall of the'conical recess 10 1 indicates the transmisforked end being received in the groove 33 to provide a direct drive between the shafts 2 and 3. Member 13 with its conical outer surfaces, and that portion of the enlarged end of shaft 2 that is provided with the internal conical recess 10, constitute companion elements of a friction clutch adapted frictionally to couple the-coaxial power transmission members to wit z-shafts 2 .and'3.

Secured to the clutch shaft 2 is the gear '14 which meshes with the counter shaft. gear 15 for driving said counter shaft. Formed on orsecured to the counter shaft are the gears 16, 17 and 18, the gear 18. being in mesh with the reverse idler gear 19.

'Slidably'monnted on the shaft 3 is the ge r 20 which when. moved to the right of the position shown in 1 meshes with the gear 17 "to provide low gear and when moved to the left, from its neutral position, shown in Fig. 1, meshes with the reverse idler gearli) to provide reverse gear. This gear '20 has the grooved collar 21 in which is. received the forked end of the arm 22 carried by the shifter rod 23. The shifter rod'23ywill 'be operated by the shift lever 24 in the usual manner.

' At all times in mesh with the gear 16 is the gear 25 which is normally freely rotatable on the conical member 25' which is splined and secured to the driven shaft 3. Formed-on one face of the gear 25 is the extension 26- having the "circumferentially extending groove 27 and formed interiorly of the extension are the teeth 28. 7

The inner internal conical part of gear 25 and the external conical member 25 constitute companion elements of a friction clutch adapted to couple frictionally the coaxial power transmitting members 3 and 25.

- Slidably mounted on the driven shaft 3 is the coupling member 29 having the external teeth 30 adapted when shifted to the right.

of the neutral position shown in Fig. 1 to mesh with the internal teeth 11 of the shaft 2 and when moved to the left of the neutral position shown in Fig. 1 to mesh with the internal teeth 28 of the gear 25. The coupling member is operated through means of the arm 31 carriedv by the shifter rod 32, the lower end of the arm being forked and said of the coupling member.

Member 29 constitutes a double-ended element of two jaw clutches, the jaws or teeth on one end of which are adapted to be intermeshed with the companion jaws or teeth 11 on shaft2 and those on the other end to be intermeshed with the companion jaws or teeth 28 on gear 25, thus positively coupling in the one case coaxial transmission members 2 and 3 and in the other case coaxial transmission members 3 and 25.

For drawing the conical recessed end of the shaft 2 into engagement with ,the con? :al member 13 and the gear 25 into engagement ssaasi chronization occurs. As these yokes and their associated parts are of a similar construction a detailed description of one will suflice for both." As shown in 2 the yokes 'are pivotally mounted on the pins 36 which pass through the sides of the transmission casing or housing and the yokes are adapted for rocking movement u on operation of the shifter rod 32. Pivotal y mounted adjacent the lower ends of the arms of the yokes by means of the pins 37 are the thrust blocks 38, the thrust blocks carried by the yoke 35 being received in the circumferentially extending groove 27 of-the gear 25 while the thrust blocks carried by the yoke 34 are received in the circumferentially extending groove 12 of the enlarged end 9 of the shaft 2. Each of the yokes has formed therein a recess, the lower end of which is reduced in diameter thus forming chambers 39 and 40. The lower end of the plunger 41 is of a diameter to form a sliding fit in the chamber 40, said plunger having a flange 42 and an extension 43, the

, extension passing through a central opening formed in the threaded cap 44 received in the outer threaded end of the recess. A coiled spring 45 surrounds the plunger 41 between the flange or collar 42 and the shoulder 46' formed by the reduction in the diameter of the lower end of the recess, said coiled spring normally holding the plunger in its raised position as shown more particularly in Fig. 2 of the drawings. The extension 43 of the plunger constitutes a latch bolt which bears against the shift rod 42; its end is semispherical.

For introducing or supplying a lubricant to the chamber 39 I provide an opening 47 through which the lubricant is introduced by splashing due to the operation of the transmission gears. This lubricant is allowed to pass into the chamber 40 through the groove 48 formed longitudinally of that portion of the plunger operating within the chamber.

The shifter rod 32 shown more particularly in Fig. 3 of the drawings is formed with the longitudinally spaced elongated recesses 49 and 50, the ends'of the recesses being rounded substantially the same radius as the semispherical ends of the extension 43 of the plunger thus forming keepers. Extending from that end of the recess 49 adjacent the shifter arm 31 is the inclined surface 51 which terminates into the rounded recess 52. Ex- I tending from that end of the recess 50, adj acent the shifter arm 31, is the inclined surface 53 which terminates into the rounded recess 54.1 Secured to and positioned between the yokes 34 and 35 is the coiled spring 55' which normally tends to rock the upper ends of the yokes towards each other, 'such move ment being limited by the stop 56 secured in the casing or housing 1 which engages an ear or projection 56' which is formed on or se-, cured to the yoke.

- The conical member 25 is formed with the annular groove 57 which is intersected by the helical groove 58 also formed in the conical member and extending the entire length thereof. Communicating with the annulargroove 57 and for supplying lubricant thereto, are one or more openings 59 formed in the gear 25 and extending from the bottom of the surface between adjacent teeth as more particularly illustrated in Figs. 1 and 4 of the drawings. As the gear 25 rotates in mesh with the gear 16 the lubricant gathered by the teeth of these gears is forced through the.

openings 59 into the annular groove 57 and passes through the spiral groove 58.

Positioned within an extension on the casing or housing 1 is a ball bearing 60 adapted to be operated by the fork 61 carried by the clutch rock shaft 62 and the purpose of this bearing is to take the thrust of releasing the clutch which connects the motor to the transmission through means of the sleeve 63. This clutch may be of any convenient conventional form. The outer race of the roller bearing 5 is held within the transmission casing or housing against both rotatable and longitudinal movement by means of the pin 64, the lower end of the pin being reduced and received in an opening formed in the race.

In the drawings the parts are shown in neutral position. To shift into low speed or into reverse? gear the gear 20 is operated from the shifter rod 23 in the usual manner. It is the purpose of the present invention to synchronize the transmission elements so that the coupling member 29 may be shifted into position for second or high speed without clash. lVhen it is desired to shift into second gear the shift lever 24 is opcrated to move theshifter rod 32 to the right as shown in Fig. 3 and to the left as shown in Fig. 1, this movement of the shifter rod causing shoulder 49a at that end oftherecess 49 thrust blocks 38 will force the gear. 25 into tight frictional engagement with theconical member 25- so that the gear will rotate withthe conical member and establish a synchronized condition between thesgear 25 and the coupling 29 in order that the'teeth'28 of the gear ma'y be readily meshed with the teeth 30 of the coupling without clash. The resist- .ance developed by the gear 25 being placed into tight frictional engagement with the conical member 25 will cause the plunger '41 to be lowered against action of the coiled spring 45 this allowing the end of the extenthe plunger 41 therewill be a hydraulic pressure within the chamber 40 and as the plunger is lowered the lubricant within the chamber 40 will pass through the groove or passage 48 to the opposite side of the enlarged lower end of the plunger and into the chamber 39. The hydraulic pressure retards the downward movement of the plunger and if an attempt should be made to operate the shift so uickly as not to allow sufficient time for sync lronization thehydraulic pressure within the chamber 40 would be suflicient-to hold the upper end of the plunger in engages ment with the endof the recess in the shifter rod a'suiiicient length oftime to allow for proper synchronizing. This same action in-- creases the v pressure to rock the yoke and more tightly force the gear into engagement with its associated conical member. Resistance to the movement of the operating means is increased as the speed of the movement of said operating means is increased. In other words the resistance varies according to the rate of movement of the operating means. It Wlll be understood that the hydraulic pressure may be increased or decreased by varying the diameter of the plunger, the size of the chamber 40 in which the endof the plunger operates, or the size of the groove or passage 48. The engagement of the shoulder 49a at the end of the recess 49 with the end of the extension-43 of the plunger operates to restrain the shifting .of the shift rod to allow time for synchronization and as just described the dash pot efi'ect of chamber 40 and plunger 41'further augments this restraint for controlling the synchronizing time element as desired. It will be understood that the hydraulic pressure developed in the chamber 40 will vary with the viscosity of the transmission oil therein and inasmuch as the viscosity of the oil varies from time to time due to changes in temperature the retarding effect on the depression of the plunger 41 will be increased as the viscosity of the oil increases so that, as for example in cold weather, the transmission oil. becomes heavy and consequently a greater power is necessary to synchronize the gears. The hydraulic action will furnish means for allowing more time for'synchronization as well as increasing the synchronizing effect. As the extension 43 .of the plunger passes from engage;

ment with the end of therecess 49 the coiled spring 55 tends to draw the yoke towards its original or normal position against the.

b7 member 29 into engaging position with the teeth 28 of the gear 25, this movement being further augmented by the end of the extension 43 of the plunger bearing against the inclined surface 51. The engagement of the extension in the rounded. recess 52 holds the shifter rod in its shifted position. In the event that the teeth of the coupling member 29 abut the internal teeth 28 of the gear 25 said gear 25 will be tapped free of or disengaged from its engagement with the conical member 25' so as to allow the gear 25 to have a slight rotary movement in order that the teeth 28 thereof may bemeshed with the teeth-30of the coupling member 29.

The angle of the conical member 25' and its corresponding or cooperating gear 25 is such that when these two parts are brought into tight frictional engagement they will continue to transmit a substantially normal amount of torque without the aid of afial pressure from the yoke tending to hold them in tight frictional engagement while at the same time the gear 25 can be released from frictional engagement withthe conical mem ber 25' by the nominal amount of axial pressure produced by the spring when augmented by a slight blow from the coupling -member 29. What has been said relative to r the angle of the conical member 25' and its 7 associated gear 25 is applicable to the conical member 13 and its associated member 10 formed on the inner end of the shaft 2.

Thehelical groove 58 in the conical member 25 is in such a direction as to, when op-- erating under the severest load conditions, have a tendency through the screwing action of thisspiral to draw the conical member and gear together to increase the frictional effect upon the members. Another advantage to be gained by this spiral groove 58 is that it breaks up the surface of the conical member 25' so that during the clutching action the surplusfilm of oil can be squeezed out more readily as the distance it must flow is lessened.

Considerable importance is attached to the selection of the material for the friction surfaces of the conical members and their associated members adapted to be brought into frictional engagement therewith. In actual practice I have found it advantageous to have one of said members of an extremely hard material such as hardened steel and the other member of a relatively softer material composed of soft matrix in which embedded very hard crystals for supporting the loads, for example certain bronze alloys.

In going'from second gear to .high gear it will be understood that the shifter rod 32 will be moved in the opposite direction and operate the yoke 34, and its associated parts in the same manner as has been described operating the yoke 35, the yoke 23% being rocked through engagement of the extension 43 of the plunger 41 of that yoke with the shoulder 50a at the end of the recess 50.-

When the yoke 34 is operated the enlarged re- .cessed end 10 of the shaft 2 is drawn into When the coupling member is in neutral position it is spaced sufiiciently far away from the members with which it is to'be meshed so that before the' teeth of the coupling member mesh with the teeth of the cooperating power member thereis suihcient movement of the shifter rod to efiect'engagement of the synchronizing members, to allow for normal wear between said synchronizing members, and to allow the extension 423 of the plunger carried by the yoke to pass from engagement with the end of the recess with which it is normally engaged in neutral position.

' Fig. 5 of the drawings have illustrated a slightly modified form of synchronizing control and shifter mechanism in which "a portion of the transmission casing or housing 1 is provided with the extending ledges -and 66 forming the elongated recess 67 therebetween. A ball 68 is operable in an opening 69 formed in the casing or housing 1 and is normally pressed outwardly by means of the coiled spring 70. At 71 I have shown a shifter rod corresponding to the shifter rod 32 and said shifter rod 71 is provided with the elongated recesses 72 and 3. Secured to the rod 71 is the arm 31 which is adapted to operate the shiftable member 29. Slidably mounted on the shift rod 71 is the member 74, said member 7 4 being oper ated through means of the shift lever 24.

' The member 74 bears on the shift rod only at each end and there are bridge portions connecting thetwo ends and passing around the arm 31. Formed in the member 74 are the openings 75 and 76 in which are received the balls 77 and 78, the balls being engageable in the recesses 72 and 73 respectively and normally on opposite sides of that portion of the rod between the recesses. Formed adjacent the end of the member-74 opposite tothat having the o' nings 75 and 76 are the concaved recesses 9, 80 and 81 in which the ball 68 is adapted to engage, the ball being shown in neutral position of the parts as engaging within the recess 81. The member 74 is provided with the longitudinally spaced elongated recesses 82 and 83, the inclined surfaces 84 and 85, and the rounded .recesses 86 and 87 corresponding tothe recesses 49 and 50 the inclined surfaces 51 and 53, and the rounded recesses 52 and 54, shown in the shifter rod 32 more particularly in Fig. 3 of the drawings and for the same purpose as described therefor.

In the modified form of the invention disclosed in Fig. 5 the yokes 34 and 35 are illustrated as being drawn towards one another by means of the coiled spring 55. In this form of the invention instead of using the form of stop 56 disclosed in Figs. 2 and 3 of the drawings I provide a novel form of stop including a housing 88 for the slidable plungers 89 and 90, said housing being formed on or secured to the casing or housing 1. The plungers are pressed outwardly by means of the coiled springs 91 and the p outer ends of the plungers are normally in engagement with the ears or projections 56 formed on the yokes. The inner ends of the plungers 89 and 90 are received within recesses 92 formed in the housing and the upper surface of the housing is dished or recessed as shown at 93 to form areservoir for the transmission lubricant. Openings 94 extend from the dished or recessed portion 93 and communicate with the recesses 92 so that when the plungers 89 and 90 are in their outermost positions lubricant will pass into the recesses 92 and form a cushion against the return of the plungers to their normal positions. This cushioning action does away with any noise incident to the return of the yokes to their normal positions.

In the operation of the construction disclosed in Fig. 5 when the gear shift lever 24 is operated to place the members in second gear the member 74 will be moved towards the right of the figure. This movement will cause the ball 77 to rise from engagement wit-h the end of the recess 72. into the recess 67 andthis will allow the member 74 to move without movement of the shifter rod 71 and operate the yoke 35 in the manner which has been described previously as to the construction disclosed in Figs. 1, 2, 3 and 4 of the drawings. This movement of the member 74 will carry the ball 78 to position the same in enga V ement with the right hand end of the recess 3. At this point synchronization has been completed and further movement of the member 74 will cause the shifter rod 71 to be carried to the rightand through means of the arm 31 operate the shiftable member 29. The ball 7 8, when the member 7 4 is moved to the right, is held between the bottom surface of the recess 73 and the ledge 66 and is prevented from raising out of engagement from the end of the recess 73. When the member .74

V is shifted to the right, as described, the ball the ends of the recess 82 and the recess 86 such as to allow the wall of the recess 86 to press against the plunger carried by the yoke when the member 74 is shifted to the right and so" rock the yoke as to hold the gear shifted thereby in engagement with its associated conical member during the time that it is connected to the drive shaft by means of the coupling 29 for transmitting power. The member 74 when shifted to the left as shown in the figure will return the parts to their neutral position.

To provide for lost motion between the operation of the synchronizing mechanism and the operation of the shift rod to move the shiftable element I may construct the couling 29 as shown more particularly in Fig. 6 of the drawings. In this form of the invention a relatively wide circumferentially extending groove 95 is provided, this groove being wider than the arm 31 so that the arm may have movement relative to the coupling 29 before engaging the faces of the groove to move the same.

In Fig. 7 of the drawings I have shown a slightly different arrangement of the shifter rods 23 and 32 whereby the shifter rod 23 may be moved a greater distance than the shifter rod 32 upon movement or operation 7 of the shifting lever 24 it being understood than it will the rod 23. While I have illustrated the rod 32 as being adapted for movement a less distance than the rod 23 it will be understood that this operation might be reversed, if desired, and the rod 32 shifted a greater distance than the rod 23.

In Fig. 8 I have illustrated a slightly modi-.

fied form of stop for the yokes. .In the construction two links 96 and 97 are provided, the link 96 being pivotally connected to the yoke and the link 97 pivotally connected to the casing or housing of the transmisison.

A flat orleaf spring 98 is inserted over the pivotal points as shown so that when the top of the yoke is swung to the right this spring willdepress the joined ends of the two links 96 and 97 and allow the yoke to be moved to the right. When the yoke isreturned toits normal position these linkswilllimit its movement and does so without any click or noise as might be the case if they returned e) ainst a solid stop where it would strike a Having fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. A power transmission including power transmission elements one of which is shift-v able relative to the other, means for syn.- chronizing the speeds of the elements, a swinging member adapted for operating the synchronizing means, means for operating the shiftable element and swinging member, and hydraulic means carried by the swinging member and engageable with the operating means for retarding the movement of the operating means.

2. A power transmission including power transmission elements one of which is shiftable relative to the other, means for synchronizing the speeds of the elements, a swinging power multiplying member adapted to operate the synchronizing means, a shifter rod adapted to operate the shiftable element and swinging member, and a slidable plunger carried by the swinging member and engageable with the shifter rod for retarding the movement thereof.

3. 'A power transmission including power transmission elements one of which is shiftable relative to the other, means for synchronizing the speeds of the elements, av

swinging power multiplying member adapted to operate the synchronizing means, a shifter rod adapted to operate the shiftable element and swinging member, and a spring controlled slidable plunger carried by theswinging member and engageable with the shifter rod for retarding the movement thereof,

4. A power transmission including power transmission 'elementsone of which is shiftable relative to the other, means for synchronizing the speeds of the elements, a

swinging -memberadapted to operate the;

synchronizing means, a shifter rod adapted to operate the shiftable element and swinging member, and a hydraulically controlled slidable plunger carried by the swlnging member and engageable with the shifter rod for retarding the movement thereof.

5; A power transmission including power transmission elements one of which is'shiftable relative to the other, means for synchronizing the speeds of the elements, a swinging member adapted to operate the synchronizing means, a shifter rod adapted to operate the shiftable element and swinging member, and

a hydraulic and spring controlled slidable plunger carried by the swinging member and enga cable with the shifter rod for retarding t e movement thereof.

6. A powertransmission including power transmission elements one of which is shiftable relative to the other, means for synchronizing the speeds of the elements, a swinging lowing operation of the shiftable element as.

.power shaft and means for rotating the same.

bearing, a second power element shiftable meager 'member with the end of the recess.

7. A power transmission including power transmission elements one of which is shiftable relative to the other, means for synchronizing the speeds of the elements, a swinging power multiplying member adapted to operate the synchronizing means in its swinging movement, a shifter rod adapted for operating the shiftable element and swinging memher, said shifter rod having a recess formed therein, and means carried by the swinging member and normally engaged in the recess of the shifter rod, the end of the recess in the movement of the shifter rod engaging the member carried by the swinging member for initially operating the synchronizing means and allowing operation of the shiftable element as said means carried by the swinging member moves from engagement with the end of the recess.

8. A power transmission including power transmission elements one of which is shiftable relative to the other, means for synchronizing the speeds of the elements, a swinging power multiplying member adapted to operate the synchronizing means, a shifter rod adapted for operating the shiftable element and swinging member, said shafter rod hav ing a recess formed therein, and a slidable plunger carried by the swinging member with its end normally received in the recess the end of the recess in the movement of the shifter rod engaging the plunger for initially 7 operating the synchronizing means and althe end ofsaid plungerpasses from engagement with the end of the recess. 7

9. A power transmission including power transmission elements one of which is shiftable relative to the other, means for synchronizing the speeds of the elements, a shifter rod for operating thesynchronizing means i and shiftable element, said shifter rod having a recess formed therein and an inclined surface adjacent one end of said recess, and 12 means engageable with the end of the recess for retarding the movement of the shifter rod and to ride over the inclined surface to accelerate movement of the shifter rod.

10. A power transmission including a a conical bearing mounted on'the shaft and having a helical-groove therein, a power element normally freely rotatable relative to the relative to the first mentioned element, means for effecting tight frictional engagement between the normally freely rotatable element and its conical bearing to effect synchroniza- I tion of the speeds of the power elements, and

the bearing, a second power element shiftable relative to the first mentoned element, means for effecting tight frictional engagement between the normally freely rotatable element and its conical bearing to effect synchronization of the speeds of the power elements, and means for operating the shiftableelement.

12. A power transmission including a power shaft and means for rotating the same, a conical bearing mounted on the shaft and having a helical groove therein, means for supplying under pressure a lubricant to the groove, a power element normally freely rotatable relative to the bearing, a second power element shifta'ble relative to the first mentioned element, means for effecting tight frictional engagement between the normally er shaft and means for rotating the same, a

conical bearing mounted on the shaft, a power element normally freely rotatable relative to the bearing, one of said members being of relatively hard material and the other of relatively soft material, a second power element shift-able relative to the first mentioned element, means for effecting tight frictional engagement between the normally freely rotatable element and its conical bearing to effect synchronization of the speeds of the power elements and means for operating the shiftable element.

14. A power transmission including a power shaft and means for rotating the'same, a conical bearing mounted on the shaft, a power element normally freely rotatable relative to the bearing, one of said members being of relatively hard material such as hardened steel and the other being of, relatively soft material such as bronze, a second power element shiftable relative to the first mentioned element, means for effecting tight frictional engagement between the normally freely rotatable element and its conical bearing to effect synchronization of the speeds of the power elements and. means for operating the shiftable element.

15. A power transmission including a power shaft and means for rotating the same, a bearing mounted'on the shaft, a power element normally freely rotatable relative to the bearing, a second power element shiftable relative to the first mentioned element, means for effecting tight frictional engagement and subsequent release of the normally freelyro- .tatable member and its bearingto effect synchronization ofthe speeds of the power elements, and means for operating the shiftable element, the shiftable element being so spaced relative to the first mentioned element as to allow synchronization to take place prior to engagement of the elements.

16. A power transmission including a power shaft and means for rotating the same, a bearing mounted on the power shaft, a power element normally freely rotatable relative to thebearing, a shiftable power element adapted to be engaged..,with the first mentioned powerelement, means for effecting tight frictional engagement between the first mentioned power element and its bearing to effect synchronization of the speeds of the power elements and to operate the shiftable member, and means for retarding the movement of the last mentioned means to effect proper s nchronization, the shiftable power element eing so spaced relative to the other power element as to allow for wear between the normally freely rotatable power element and its bearing, to ermit release of the retarding means, an to permit proper synchronization prior to engagement of the power elements.

17. A power transmission including power elements adapted to be moved into or out of driving relation, means for synchronizing the recesses formed therein and an inclined surface adjacent one end of each of said recesses, and members normally received in'each of the recesses and engageable with one end thereof for retarding the movement of the shifter rod in either direction, one of said members being adapted to ride over an inclined surface in movement of the shifter rod in either direction to accelerate the movement of the shifter rod.

19. A power transmission including spaced power transmission elements, a shiftable power element mounted. between the first mentioned elements and adapted to be moved into engagement with either one of the' first till mentioned el ments, means'for synchronizing the speeds of the elements, a shifter rod for operating the synchronizing means and shiftable element, said shifter rod having spaced recesses formed therein and an inclined surface adjacent one end of each of said recesses, and yieldable members normally received in each of the recesses and engageable with one end thereof for retarding the movement of the shifter rod in either direction, one of said members being adapted-to ride over an inclined surface in movement of the shifter swinging YiiilhlbGI for normally holding the power element released from its bearing, and means for operating the shiftable element.

21. A power transmission including a shaft, a conical bearing mounted on the shaft, "cment normally freely rotatable o the bearing, a shiftable power element llli u liedl on the shaft, a swinging mem be;- znlapte-cl to establish tight frictional engagement between the normally freely rotatable power element and its bearing to effect synchronization of the speeds of the power elements, means connected to the swinging member for normally holding the power element released from its bearing, means for limiting the releasing movement of the swinging element, and means for operating the shiftable element.

22. A power transmtssion including a shaft, a conical bearing mounted on the shaft,

. a power element normally freely rotatable relative to the bearing, a shiftable power element mounted on the shaft, a swinging member adapted to establish tight frictional engagement between the normally freely rotatable power element and its bearing to effect synchronization of the speeds of the power elements, means connected to the swinging member for normally holding the power element released from its bearing, an abutment engageable with the swinging member for limiting the releasing movement thereof, and means for operating the shiftable element.

23. A power transmission including a shaft, a conical bearing mounted on the shaft, a power element normally freely rotatable relative to the bearing, a shiftable power element mounted on the shaft, a swinging member adapted to establish tight frictional engagement between the nori'nally freely rotatable power element and its bearing to cifect synchronization of the speeds of the power elements, means connected to the swinging member for normally holding the power. element released from its bearing, hydraulic cushioning means for limting the releasing movement of the swinging member, and means for operating the shiftable element.

'24. A synchronizing clutch comprising a pair of members having co-acting conical sur faces, one of said members having an annular groove intersected by a spiral groove which extends the entire length of the member, said grooves removing surplus lubricant and increasing the frictional engagement between the members. 25. A power transmission including spaced power transmission elements, a shiftable power element 'mounted between the first mentioned elements and adapted to be moved into engagement with either one of the first mentioned elements, means for synchronizing the speeds, of the elements, a shifter rod for operating the synchronizing means and shiftable element, said shifter rod having spaced recesses formed therein on opposite sides of the shiftable element, and members normally received in each of the recesses and engageable with the ends thereof adjacent the shiftable member for retarding the movement of the shifter rod in either direction.

26. A power transmission including spaced power transmission elements, a shiftable power element mounted between the first mentioned elements, and adapted to be moved into engagement with either one of the first mentioned elements, means for syn chronizing the speeds of the elements, a shifter rod for operating the synchronizing means and shiftable element, said shifter rod having spaced recesses formed therein on opposite sides of the shiftable element and inclined surfaces between the recesses and shiftable element, and members normally received in each of the recesses and engageable with the ends thereof adjacent the shiftable member for retarding the movement of the shifter rod in either direction, one of the members being adapted to ride over an in clined surface in movement of the shifter rod in either direction to accelerate the movement of the shifter rod.

27. In a power, transmission mechanism, two power transmitting members each equipped with one of two intermeshable toothed elements in torque, transinitting relation, one ofthe' toothed elements being movable into and out of interlocking engagement with its companion; a friction clutch element in torque transmitting relation to each 'memher, one of said friction clutch elements being movable into and out of frictional driving engagement with its companion; means for releasably connecting one ofsaid friction clutch elements to one of said toothed eleing said movable toothed element and friction clutch elements toward interdriving relation with their companions.

28. A combination as defined in claim 27 in which the fluid internal resistance brake is of the hydraulic type.

29. A combination as defined in claim 27, in which said transmission mechanism is incased in a housing adapted to contain lubri-.

eating oil, and said fluid internal resistance brake arranged to oppose the releasing movementof the lock consists of ardashpot, in further combination with means to supply the dash pot chamber with lubricant contained within the housing.

30. A combination as defined in claim 27 in which said'transmission mechanism is enclosed in a housing adapted to contain lubricating oil, and said fluid internal resistance brake arranged to oppose the releasing movement of the lock consists of a dashpot, the

chamber wall of which is provided with an oil inlet arranged to receive lubricating oil' splashed by the transmission and direct it by gravity into the chamber.

31. A combination "as defined in claim 27 in which. saidself-acting lock comprises a latch bolt movable transversely of the direction of. relative movement of the friction clutch elements and 'a spring arranged to bias said latch bolt to locking position.

32. In power transmission mechanism, two coaxial power transmitting members, each equipped with one of,two-intermeshable 'j aw clutch elements and one of two interengageable-friction clutch elements in torque transmltting relation to the members; one of the jaw clutch elementsbeing movable axially into and out of mesh with itscompanion; one

of said friction clutch elements being mova;

- ble axially into and out of frictional driving ternal resistance brake arrangedtoresist the engagement with its companion, and having a range of coupling and uncoupling movement shorter than the range of coupling and un-.

coupling movement of the movable jaw clutch elements; means for releasably connecting one of the friction clutch elements to one of the jaw clutch elements including a keeper and a cooperating latch bolt movable transversely of the path of movement of the axially movable friction clutch element, a spring arrangedto-bias said latch bolt into position .to interlock with said keeper, and a fluid inreleasing movement of the latch .bolt.

33. A combination as defined'jin claim 32 in which the releasable connecting means that v connects the movable friction clutch element to the movable jaw-equipped member cona shifter yoke engaging the movable friction clutch element, said shifter yoke and slidable shifter rod carrying, one on each, said movable latch bolt and keeper; and a shift lever for sliding the shifter rod. 34;. A combination as defined in claim 32 in which the releasableconnecting means that connects the movable friction clutch element to the movable jaw-equipped member consists of a shifter .arm engaging the movable jawequipped member, a slidable shifter rod to which said shifter arm is rigidly united, and a shifter yoke consisting of a lever having its power arm releasably engaging said shifter rod by means of saidlatch bolt and a shorter work arm engaging the movable friction clutch elementto one of said jaw clutch elements for effecting simultaneous axial movement, said means comprising a self-acting lock biased to locking position and releasable in response to adequate pressure of-one v friction clutch element against its companion, and manually controllable means for axially moving one of the jaw-equipped members and thereby the releasably connected friction clutch element toward their'companions.

36; In power transmission mechanism, a power shaft, a power transmitting element normally loose thereon, said power transmitting element being equipped with clutch jaws and a conical friction clutch surface; companion elements .equippedwith clutch jaws and a conical friction surface in torque transmitting connection with said shaft; one of being axially movable with respect toone of said conical friction surfaces';'means for releasably connecting one of said friction surface-equipped members to one of said jaw axial movement, said means comprising a self-acting lock biased to locking position and releasable in response to adequate pres (sure of one friction surface against its companion; and manually controllable means for I moving one of the jaw-equipped elements and thereby the releasably connected friction surface-equipped element toward their companion's. i

37. In a power transmission, mechanism,

said j aw-e'quipped elements surrounding and 1 equipped members for effecting simultaneous two coaxialpowertransmitting members; a

iaw clutch element non-rotatively secured to each member, one of said jaw clutch elements being movable into and out oi mesh with its companion; a friction clutch element non-rotatively secured to each member adjacent each jaw clutch element, one of said friction clutch elements being movable into and out of frictional driving engagement with its companion and having a range of coupling and uncoupling movement shorter than that of the movable jaw clutch element; means mechanically connected to said movable jaw clutch element and said movable friction clutch element whereby initial movement of the former-toward its companion moves the latter towardits companion, said means including an elastically yieldable member and a fluid internal resistance brake associated therewith, said brake being arranged to become efiective in response to interengagement of the friction clutch elements so as to resist and delay further movement of the jaw clutch element, said means being further constructed and arranged to relieve the resistance to advance of the jaw clutch element into engagement with its companion in responseto a force,

of the friction clutch eledue to the contact ments, sufiicient to overcome the elastic and fluid brake resistance.

38. A power transmission mechanism including power transmission elements relatively shiftable into and out of interdriving engagement, frictional means for synchron izing speeds of the power transmission elemerits, a mannallycontrollable lever for effecting interengagement oi the power transmission elements and synchronizing means; mechanical connections in parallel between said lever, one of the power transmitting elements, and the frictional synchronizing means, said power transmitting element having a lon er range of movement than that of the frictional synchronizing means; and a fluid friction brake rendered efi'ective by engagement of the frictional means and arranged to prolong the engagement of the frictional means to delay the engagement of the power transmission elements.

39. In power transmission power transmitting.- members, with one of two intermeshable toothed eleable with the other movable e mechanism, two

each equipped movable toothed element so that they are compelled to move in unison toward their companions, saidmeans comprising a keeper in fixed relation to one of said movable elements, a self acting lock lunger, movement, biased to engage the keeper, and operable in a direction transverse of the movement of said movable elements toward interengaging position, means constructed and arranged yieldably to resist releasing movement of the lock plunger; and havin the characteristic of increasing resistance ln proportion to increasing speed of the lock plunger during its releasing movement, said plunger being releasablein response to adequate pressure of one friction element against its companion when the toothed element is moved toward its com anion and manually controllable means or moving said toothed element toward and into interlocking engagement with its companion.

In testimony whereof I hereunto afiix my signature.

EARL A. THOMPSON,

' llld ments in torque transmitting'relation, one of the toothed elements being movable ax ially ment with its companion; a friction clutch into and out of interlocking engageelement in torque transmitting relation to each member, one of said friction clutch elements being movable into and out of frictional driving engagement with its companion', and having a lesser amplitude of the movable toothed element; means for releasablyconnecting the movable friction clutch element with the 

